The Part Abuse Problem is dragging all kinds of previous, half-forgotten hacks out of the woodwork, however this has obtained to be essentially the most classic: [KenS] began utilizing a transformer as a variable choke on his audio system 55 years in the past.
The hack is fairly bone-dead easy. A choke is an inductor in an audio (or another) circuit designed to, properly, choke off higher-than-desired frequencies. We featured a deep dive a number of years again in case you’re . An inductor is a coil of wire, normally (however not essentially) wound round a core of iron or ferrite. A transformer? Nicely, that’s additionally a coil of wire round a core… plus an additional coil of wire. So when [KenS], again in his salad days, had a tweeter {that a} was a little bit too tweety, and no correct choke, he grabbed a transformer as a substitute.
That is the place inspiration hit: certain, in case you go away the second winding open, the transformer acts like a typical choke. What occurs in case you quick that second winding? Nicely, you dampen the response of the primary winding, and it stops choking, to the purpose that it acts extra like a straight wire. What occurs in case you don’t quick the second winding, however don’t go away it broad open? [KenS] caught a potentiometer on there, and located it made a handy-dandy variable choke with which to completely tune the tone response of his audio system. Altering the resistance modifications the speed at which excessive frequencies are choked off, permitting [KenS] to get the right frequency response with which to rock out to Simon & Garfunkel, The Carpenters and The Guess Who. (In line with the Billboard Prime 100 for 1970, these are who you’d be listening to in case you had standard tastes.)
Whereas we are able to’t say the transformer is de facto being tortured on this uncommon mode, it’s actually not the way it was designed, so would qualify for the “Junk Field Substitutions” class of the Part Abuse Problem. For those who’ve made related substitutions you’d wish to share, don’t wait one other 55 years to write down them up– the competition closes November eleventh.
Transformer picture: Hannes Grobe, CC BY-SA 4.0.
